1. Field of the Invention
The present invention relates to a spindle drive for a coordinate measuring machine, wherein a spindle nut which is fastened within a receiving member is seated on a driven threaded spindle, and whereby, intermediate the receiving member and a retaining member, the former is fixedly connected with a component which is to be driven, through the interposition of roll bodies for producing a compensating clearance radially relative to the spindle axis and for compensating wobbling motions of the spindle.
2. Discussion of the Prior Art
A spindle drive of that particular type is described in the specification of German Laid-Open Patent Appln. 35 14 961. In order to prevent a radial impact from the threaded spindle from being transmitted to the component which is to be driven; in this instance, the spindle sleeve, roll bodies are arranged intermediate planar bearing or support surfaces which extend perpendicular to the spindle axis. Any wobbling motion of the spindle axis does not transmit itself to the component which is to be driven, inasmuch as the latter is movable on a spherical surface about the spindle nut. This spherical surface is extremely complex and expensive in the manufacture thereof. It is also comparatively large in size. Correspondingly large in size are the ball bearings which are arranged thereon. In order to connect the spindle nut with the spindle sleeve secured against rotation relative thereto during a rotation of the spindle, there are provided ball-and-socket joint bolts, in conformance with the disclosure of German OS 35 14 961. These engage into sleeves which are larger in diameter. As a result thereof, the turning moment or torque transmission, or, in essence, the rotationally-secured connection between the spindle sleeve and the spindle nut is not free from play.
In the disclosure of German Petty Patent 81 32 380, there is elucidated a further spindle drive for a coordinate measuring machine. In this particular drive, there is avoided any change in the position of the measuring carriage subsequent to the implemented advancing movement. The receiving or pickup member possesses a blind bore with a fitted sleeve extending at right angles to the spindle axis. A carrier trunnion engages into the sleeve, and is connected with a retainer component. Arranged within the blind bore is a bearing cage incorporating balls which are arranged about a circularly-extending line for the guidance of the carrier trunnion. Any radial impact of the spindle or wobbling movements lead to the generating of lateral forces which act on the measuring carriage. These forces can be avoided through a correspondingly complicated spindle.